Crews responded to the Devon Tower shortly before 8 a.m. Wednesday.
It isn't clear if the window washers are injured, but firefighters have reportedly managed to stabilize the scaffold and are about to launch a rescue attempt.
Within 47 minutes, the department announced that the two individuals had been rescued, KOCO reported.
The pair were at the top of a 50-level building in Oklahoma City, USA yesterday. It is the 10th tallest building west of the Mississippi River.
"Devon Energy Center creates a focal point for the company and Oklahoma City by integrating civic-scaled spaces as a vital component of its overall development". All perimeter offices have floor-to-ceiling glass to maximize daylight.